G-actuated air controlled time delay



Feb. 12, 1963 w, w s 3,077,160

G-ACTUATED AIR CONTROLLED TIME DELAY Filed Sept. 9, 1960 M 4 Sheets-Sheet 1 l6 f I '1 7 1, ,8 FIG. 2.

, I32 34 I5? I I62 /72 I I46 15a I 155 I I L I 20 I [/3 i as l I/ I F130 II 24 I 6'6 92 g 92 I 152 a4'-\ s as I I 3g- I I 32- l 78 INVENTOR WILLIAM F. WILLIAMS BY W. (9. W

ATTORNEYS W. F. WILLIAMS G-ACTUATED AIR CONTROLLED TIME DELAY Feb. 12, 1963 TTORNEYS Filed Sept. 9, 1960 Feb. 12, 1963 w. F. WILLIAMS 3,077,160

G-ACTUATED AIR CONTROLLED TIME DELAY Filed Sept. 9, 1960 4 Sheets-Sheet 3 18 FIG. 8.

FIG. 7.

INVENTOR WILLIAM F. WILLIAMS ATTORNEYS BY OM69.

@Lwwu Feb. 12, 1963 w. F. WILLIAMS G-ACTUATED AIR CONTROLLED TIME DELAY 7 Filed Sept. 9, 1960 4 Sheets-Sheet 4 FIG. 10.

134 was INVENTOR WILLIAM F. WILLIAMS ATToRNEys Patented Feb. l2, 19%3 This invention relates generally to time delay mechardsms; more particularly, it relates to a G-force operated, air controlled time delay mechanism.

Time delay mechanisms of the type to which this invention relates are employed where an element of a device must be actuated at a predetermined instant in time following the occurrence of an initial event. For example, such mechanisms may be employed to actuate apparatus for ejecting a missile nose cone at a predetermined instant in time following the launching of the missile. The subject time delay mechanism is operated by G-forces and hence is capable of use where large forces of this kind exist, such as in missiles, projectiles or in centrifuge testing equipment.

it is the object of this invention to provide a time delay mechanism so constructed as to be operated by the action thereon of high G-forces.

A further object of the present invention is to provide a time delay mechanism having means to prevent the actuation thereof before the expiration of a predetermined period of time.

Another object of this invention is to provide an air controlled timing device for a time delay mechanism, said device being so constructed as to permit a variety of values for the period of the time delay.

it is also an object of the invention to provide a time delay mechanism that is so constructed as to be independent of surrounding atmospheric conditions.

A still further obfiect of the invention is to provide a time delay mechanism so constructed as to actuate a source of compressed gas.

(Ether obiects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:

FIG. 1 is a perspective view of the time delay mechansim of the invention;

FIG. 2 is a perspective view of the time delay mech anism of FIG. 1 with most of the outer housing removed and showing the mechanism in its final position;

FIG. 3 is a top view of the time delay mechanism;

FIG. 4 is a vertical section, taken generally on the line 4--.- of 3 and showing the mechanism in its initial position, and par icularly showing the construction of the device and the triggering apparatus;

PEG. 5 is a transverse section on the line 5-fi of PEG. 4 show 1g particularly the construction of the triggering u apparatus,

PEG. 6 is a transverse section on the line 6- of PEG. 4-;

FIG. 7 is vertical section on the line 7-7 of E6. 3,

showing the mecha ism in its initial position, and particularly showing the construction of the timing device the rocke arm assembly;

8 is a vert al section on the line 7-? of FIG. 3, showing the mechanism in an intermediate position, some parts being shown in elevation;

FIG. 9 is a vertical section on the line 99 of MG. 3, with some parts in elevation, showing the rocker arm assembly and the triggering apparatus when the time delay is in its final postion; and

FIG. 16 is a side elevation, partially broken away and shown in section, and showing the triggering mechanism and the rocker arm assembly with the time delay mechanism in an intermediate position.

The time delay mechanism of the invention is responive to G-forces, or set-back forces, such as occur when an object is rapidly accelerated. in the mechanism to be described the G-forces act upon a weight mass to move the same, such movement operating an air controlled timing device. When the G-forces subside, the weight is moved toward its initial position, the velocity of such movement being controlled by the timing device. A rocker arm assembly operatively interconnects the moving weight with a triggering apparatus. When the weight has returned to its original position the rocker arm assembly releases the triggering apparatus, which then acts to puncture and open a source of compressed gas.

Referring now more particularly to the drawings, the time delay mechanism constituting the present invention is shown in perspective at 2 in PEG. 1, wherein is seen a cylindrical housing 4, a housing cap 6, and a pair of gas bottles 8 and it The bottles contain a gas under pressure and are secured in position by a clamp 12, which clamp is in turn secured by a stud bolt 14 and a nut 16. After the gas has been released from the bottles 8 and 1%, in a manner to be described hereinafter, it flows through a gas outlet 13, which is secured to the cap 6 and is in communication with the interior of the housing 4.

The time delay mechanism, with the outer housing 4 broken away, is shown in perspective in FIG. 2 (and in section in FIG. 4), wherein is seen a supporting frame 2 The frame 2'!) has an upper ring 221, a middle ring 24 and a lower ring 26 thereon, said rings 22, 24 and 26, as is best shown in H6. 4, functioning to position the frame within the housing 4. The upper ring 22 has an 0- ring 23 eated thereon in a circumferential groove, and the lower ring 26 has thereon a similarly seated O-ring 3%, said G-rings functioning to seal the frame it) in the housing '4.

Referring again to P16. 2, the time delay 1 echanism of the present invention includes a timing device, indicated generally at 32, a triggering apparatus 34, and a rocker arm assembly 36. As is best seen in FIGS. 4 and 6, the timing device 32 includes a tube 38 and a piston it the piston being loosely received within the tube for a purpose to be hereinafter described. The tube 38 is secured to a tube base 42, which base has a spherical recess 4 5 therein. A spherical bearing 46 fits in the recess 44 and has a pin which is secured to a supporting cap 2-8 by a snap ring 5b. The supporting cap it; is secured to the frame 24; axially thereof by a plurality of screws 52.

The piston is carried by an actuator shaft 54 which is disposed within a central bore 56 in the frame 2%. The shaft 54 carries a ball bearing 53 on its lower end, which bearin engages in a bearing seat as in the piston re. The piston it? is secured to the lower end of the shaft by a retainer ring as which is held in place in the piston by a snap ring 64.

A mass wei ht as is fixed to the shaft 5 said weight having a bore 5? through which the shaft passes. The weight as is secured in position by a snap ring 7% and a pin 72 and has a recess '74 in the top thereof for receiving a resilient washer 76, the washer serving as a shock absorber between the weight and a central web 21 of the frame 2b against which it abuts. The weight 66 is urged away from the supporting cap as by a coil spring '78, which spring has its upper end seated in a circumferential groove titl formed in the lower end face of the weight, and its lower end resting upon a shoulder 82 on the cap 48. The weight 66 is adapted for linear motion, there being guide bars 84 and $6 secured to the frame it) which guide the weight during such movement. The guide bars and to are secured to opposite points of the frame by pairs of screws 38 and 9G, and have bevelled side edges thereon. Four rollers 92, mounted on stub shafts 93, are provided for the weight 66 and engage the bevelled edges of the guides 84 and 86, the rollers and the guides cooperating to insure smooth linear movement of the weight.

The triggering apparatus 34 is best shown in FIGS. 4, 5 and 9, and includes a pair of cylindrical chambers 94 and 96 disposed Within the frame 21 The chambers 94 and 96 are closed at their lower ends, and have ring seals 98 and 108, respectively, disposed in circumferential grooves at their open upper ends. The bottles 8 and 11 have their lower end portions projecting into the open upper ends of the chambers 94 and 96, respectively, the O-ring seals 98 and 1% preventing the escape of gas from the chambers.

Disposed within each of the chambers 94 and 96, respectively, are actuating pins 102 and 104 and coil triggering springs 166 and 193. The actuating pins are in the cocked position shown in FIG. 4 when the mechanism is in its initial position, the triggering springs 106 and 108 being in compressed condition. The chambers 94 and 96 have aligned openings 111) and 112 extending transversely therethrough, said openings being indicated by broken lines in FIG. and by 'full lines in FIGS. 9 and 10. Flanged sleeves 113 are fitted into the openings 110- and 112. The openings 110 and 112 are positioned to confront the central portions of the actuating'pins when the coil springs 106 and 1138 are fully compressed, retainer pins 114, 116, 118 and 12!], disposed in the sleeves 113, being engageable in circumferential grooves 122 and 124 in the actuating pins 102 and 104.

The bottom walls of the grooves 122 and 124 are tapered, and the tipsof the retainer pins 114, 116, 118 and 120 are frusto-conical in shape. When it is desired to maintain the actuating pins in their depressed, or cocked, positions, the retainer pins are urged into their respective grooves 122 and 124, where they are held in position by apparatus to be described hereinafter. When it is desired to release the actuating pins the apparatus is released, and the frusto-conical tips of the retainer pins cooperate with the tapered grooves on the actuating pins, whereby the retainer pins are pushed upwardly by the force exerted by the triggering springs 106 and 108. When the retainer pins are retracted sufiiciently, the actuating pins are released. The actuating pins 102 and 104 have sharp points 126 and 128, respectively, such points functioning to puncture the bottles 8 and when the actuating pins are released. The compressed gas contained within the bottles is then released into the chambers 94 and 96, and flows therefrom through exhaust ports 130 and 132.

Referring again to the triggering apparatus 34, said apparatus is operably connected with the timing device 32 by the rocker arm assembly 36, the assembly 36 being,

best shown in FIGS. 2,7 and 8. The rocker arm assembly 36 includes a pair of rocker arms 134 and 136, which are pivotally attached to projections 138 and 140, respectively, on the frame 20. The rocker arms 134 and 136 are attached to the projections by pivot pins 142 and 144, respectively, and each of the arms is generally U- shaped in cross section. Each of the arms 134 and 136 carries a detent pin 146 or 148 at its upper end and a roller 150 or 154 at its lower end. The mass weight 66 has a pair of recesses 152 and 156 therein, the recesses being disposed on opposite sides thereof. The recesses 1 52 and 156 and the rollers 150 and 154 are in alignment when the weight is in abutment with the web portion 21 of the frame.

The arm 134 has a pair of tabs 158 thereon, which tabs bear against the retainer pins 116 and 120. The arm 136 has similar tabs 160 thereon. When the mechanism is in its initial position the tabs 158 and 16d keep the retainer pins in engagement with the actuating pins. The arms 134 and 136 are held in their initial positions by latches 162 and 164, which are pivotally attached a on the arms 134 and 136. The inner end of each latch carries a roller 176 or 178 thereon. A latch spring 184 has one end attached to the latch 162 near the outer end thereof and its other end secured to the frame 211, and functions to urge the latch upward and out of contact with the detent pin 146. The latch 164 has a similar spring 182 attached thereto.

The actuator shaft 54 of the timing device 32 is mounted for almost frictionless sliding movement within the bore- 56, the bore being provided with linear ball bearing bushings 184 to insure such movement. The bushings are secured in position in the bore by a snap ring 186. The shaft 54 passes through the busmngs 184, and has a rounded upper end 188 thereon.

The timingdevice 32 depends upon surrounding gas for its operation. As indicated above, the piston 48 is loosely received Within the tube 38, there being a small clearance therebetween. Initially, when the mechanism is assembled the tube 38 contains a gas, usually air, at a pressure the same as the pressure of the medium surrounding the device. Normally the time delay 'mechanism is merely assembled in an area where the desired air pressure and density are present. When the piston 40 moves downwardly in the tube the" gas initially contained therein is forced out through the space between the piston and the tube. When the piston moves upwardly gas will flow into the tube through the clearance between the piston and the tube, tending to equalize the pressure within the tube with that of the surrounding gaseous medium. The rate at'which the piston travels is determined by the rate at which gas flows through the clearance between the piston and the tube, which rate of flow is largely determined by the area of such clearance space. Thus, by employing ditferent clearances, diifercnt rates of travel of the piston will result.

It is usually desirable to maintain the surrounding gaseous medium at a constant pressure and density, to insure that the timing device will operate to give the desired time delay regardless of where the mechanism is employed. This is especially important when the mechanism is employed in a missile, where it may initially be at sea level and finally at a very high altitude.

Theframe 20 is disposed within the housing 4 in order to insure a relatively steady state for'the surrounding gaseous medium, the frame being sealed in the housing by an upper washer 190 and a lower washer 192. The stud bolt 14 has its lower end portion screwed into a threaded portion 194 of the bore 56, an O-ring 196 providing a seal therebetween.

The operation of the time delay mechanism will now be described. Initially, as shown in FIG. 7, the actuatmg pins are placed in their cocked positions and are held therein by the retainer pins 114, 116, 118 and 120, the rocker arms 134 and 136, with their attached tabs 158 and 160, holding the retainer pins in position.

The latches 162 and 164 are lowered for engaging the notches 172 and 174 thereof with the detent pins 146 and 148 of the rocker arms 134 and 136. The weight 66 is in abutment with the frame 20, and the actuator shaft 54 is fully inserted into the central bore 56. The rollers 176 and 178 carried by the latches are in engagement with the shaft 54, which prevents the latches from disengaging from the detent pins 146 and 148.

The frame 20 is disposed within the housing 4, and the bottles 8 and 18 are secured in position. The assembled mechanism is placed base down in a missile or other vehicle with the shaft 54 generally aligned with or parallel to the missile axis. When the missile carrying the mechanism is rapidly accelerated, the G-forces thus created will act upon the weight 66, moving it downwardly relative to the frame 2%. As the weight moves the shaft 54 is carried with it, and the piston 46 is advanced into the tube 38. The rate of travel of the piston, and hence the weight, is dependent upon the rate of flow of gas from the tube. As acceleration continues the weight continues its downward movement, and the upper end of the shaft 5d will move downwardly sufficiently to clear the rollers 176 and 173, after which the latch springs 18% and 182 will cause the latches to pivot upwardly and disengage the detent pins 146 and 148. FIG. 8 shows the mechanism just after the latches have been disengaged.

Disengagement of the latches will not immediately free the arms 134 and 136 for pivotal movement, for as the weight 66 moves downwardly the rollers 150 and 154 engage the outer surface thereof. The rocker arms 134 and 135 are not free to pivot while the rollers 150 and 154 so engage the weight. The weight will continue to move downwardly, however, for compressing the weight spring '78 until the piston 40 engages the tube base 42. It will remain in such position until the G-forces subside to a point where the spring 78 exerts a counteracting force sufficicnt to cause upward movement of the weight. When such a point in time is reached, the weight 66 is moved upwardly by the spring 78, the rate of travel being determined by the rate at which gas flows back into the tube 33. When the weight abuts the frame 20 the recesses 152- and 156 become aligned with the rollers 15% and 154. The rocker arms 134 and 136 are then free to pivot, because the lower ends thereof can move inwardly, and the latches 162 and 164 are no longer restraining the arms for pivoting.

As has been described hereinabove, the actuating pins Hi2 and 104 are restrained from movement by the retainer pins 114, 116, 118 and 129, said pins being held in position by the tabs 158 and 169 carried by the rocker arms 134 and 136. For so long as the rocker arms are restrained from movement, either by the latches 162 and M4 or by the impingement of the rollers 156 and 154 on the weight 66, the retainer pins remain in position. However, when the rocker arms become free to pivot, the triggering springs 1% and 1% will urge the actuating pins 192 and 164 upwardly. The tapered grooves 122 and 12.4 carried by said actuating pins cooperate with the conical surfaces on the retainer pins to translate a portion of the upward force exerted by the springs 195 and 1&8 into horizontal forces for causing the retainer pins to retract into their sleeves 113, when the actuating pins will be fully released. The mechanism is shown in FIGS. 2 and 9 after release of the actuating pins.

Upon release, each of the actuating pins is propelled by its associated spring and punctures one of the bottles 3 or 1%, thereby releasing a pressurized gas contained therein. Such gas will flow out of the chambers 94 and .96, through the ports 13% and 132, into the space between the frame 2% and the housing 4, and then through the gas outlet 18. The gas flow may then be used for any desired purpose, such as to operate a valve, or a switch, or some other mechanism.

The gas outlet 13 is attached to the frame 29. Referring to H6. 7, the outlet is seen to include an outlet body 198 which is secured to the frame 20 by screws 209. The body 198 has a bore 202 therein in which a valve spring 24%- is disposed, the spring serving to normally keep a valve core 266 in engagement with a valve seat 2&8 carried by the frame 26. The valve core has an O-ring 210 disposed in a groove therein, the O-ring functioning to seal the valve core to the valve seat. A threaded outlet 212 communicates the bore 262 with the exterior of the body 1%.

The valve spring is designed to exert a force sufficient to maintain the initial gas pressure within the mechanism until the bottles 8 and it are punctured, and to then permit the valve core to unseat sufficiently from the valve seat to permit the resultant gas flow to escape from the mechanism.

While the actuating pins in the mechanism as described function to puncture bottles of compressed gas, it is to be understood that they might also be employed to activate other elements. For example, they might be designed to impinge upon high explosive detonator caps, and hence function to detonate a warhead. The actuating pins might also be designed to initiate an electrical contact between two elements of an electrical circuit. In all such applications the timing device, the triggering apparatus and the rocxer arm assembly of the invention would function as hereinabove described.

Obviously, many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. A time delay mechanism, including a frame having therein a central bore extending longitudinally therethrough and at least one elongated chamber disposed to extend parallel to said bore, an elongated actuator shaft disposed for sliding movement within said bore, a G-force operated timing device, said device including a tube attached to said frame concentrically about the central axis of said bore and in position to confront the lower end of said shaft, said tube being closed at its lower end, a piston attached directly to the lower end of said shaft and disposed within said tube, the effective cross-sectional area of said piston being slightly less than the internal cross-sectional area of said tube to thus define an annular flow space therebetween, a weight connected to said shaft and spaced from said piston, said weight having a least one longitudinally extending plane surface thereon disposed parallel to the central axis of said bore and spaced from said axis a distance greater than the external surface of said tube, and spring means disposed etween said frame and said weight for urging the latter away from said tube, a triggering apparatus spaced axially from said timing device, said apparatus including an actuating pin disposed within said chamber and having a groove in the external surface thereof, a triggering spring disposed within said chamber and arranged to exert force upon said actuating pin when said actuating pin is depressed thereagainst, said frame having a transverse opening extending therethrough disposed to intersect said chamber and to confront said groove on said actuating pin when said actuating pin is in a cocked position depressed against said triggering spring, and a retaining pin disposed within said transverse opening and arranged to engage within said groove for retaining said actuating pin in said cocked position, and means interconnecting said timing device and said triggering apparatus, said interconnecting means including at least one elongated rocker arm pivotally attached centrally thereof to said frame, the upper end or said rocker arm being engageable with said retaining pin and the lower end thereof being engageable with said longitudinally extending plane surface on said weight, said rocker arm being arranged whereby when said lower end thereof is in engagement with said plane surface said upper end thereof will engage and hold said retaining pin in position to secure said actuating pin, said plane surface having a recess therein near one end thereof of a size to receive said lower end of said rocker arm, said lower end of said rocker arm and said recess being brought into registry when said weight is sufficiently shifted in response to G-forces over a period of time as determined by said timing device, whereupon said rocker arm will pivot and said retaining pin and said actuating pin will be released.

2. A time delay mechanism as recited in claim 1, wherein said frame is encased within a housing, whereby said timing device is sealed from the surrounding atmosphere.

3. A time delay mechanism as recited in claim 1, including additionally a latch means to prevent premature pivoting of a said rocker arm, said latch means including a spring-biased latch pivotally attached to said frame and engageable with said actuator shaft and with the upper end of said arm.

4. A time delay mechanism as recited in claim 1, wherein said chamber is open at one end thereof, and including a bottle containing a compressed gas, said bottle being secured to said frame and being disposed with a portion thereof exposed within said chamber in a position wherein said actuating pin will puncture the same when it is released from said cocked position. 7

5. A time delay mechanism as recited in claim 4,

8 wherein said frame is encased within a housing, said timing device being sealed from the surrounding'atmosphere by said housing, and including a gas outlet secured to said frame, and a port meansgfor communicating said I chamber with said gas outlets, the gas released from said 2,485,949 Wilson Oct. 25, 1949 2338;463 Jasse May 31, 1960 2,951,444 Hunt et a1. Sept. 6, 1960 

1. A TIME DELAY MECHANISM, INCLUDING A FRAME HAVING THEREIN A CENTRAL BORE EXTENDING LONGITUDINALLY THERETHROUGH AND AT LEAST ONE ELONGATED CHAMBER DISPOSED TO EXTEND PARALLEL TO SAID BORE, AN ELONGATED ACTUATOR SHAFT DISPOSED FOR SLIDING MOVEMENT WITHIN SAID BORE, A G-FORCE OPERATED TIMING DEVICE, SAID DEVICE INCLUDING A TUBE ATTACHED TO SAID FRAME CONCENTRICALLY ABOUT THE CENTRAL AXIS OF SAID BORE AND IN POSITION TO CONFRONT THE LOWER END OF SAID SHAFT, SAID TUBE BEING CLOSED AT ITS LOWER END, A PISTON ATTACHED DIRECTLY TO THE LOWER END OF SAID SHAFT AND DISPOSED WITHIN SAID TUBE, THE EFFECTIVE CROSS-SECTIONAL AREA OF SAID PISTON BEING SLIGHTLY LESS THAN THE INTERNAL CROSS-SECTIONAL AREA OF SAID TUBE TO THUS DEFINE AN ANNULAR FLOW SPACE THEREBETWEEN, A WEIGHT CONNECTED TO SAID SHAFT AND SPACED FROM SAID PISTON, SAID WEIGHT HAVING A LEAST ONE LONGITUDINALLY EXTENDING PLANE SURFACE THEREON DISPOSED PARALLEL TO THE CENTRAL AXIS OF SAID BORE AND SPACED FROM SAID AXIS A DISTANCE GREATER THAN THE EXTERNAL SURFACE OF SAID TUBE, AND SPRING MEANS DISPOSED BETWEEN SAID FRAME AND SAID WEIGHT FOR URGING THE LATTER AWAY FROM SAID TUBE, A TRIGGERING APPARATUS SPACED AXIALLY FROM SAID TIMING DEVICE, SAID APPARATUS INCLUDING AN ACTUATING PIN DISPOSED WITHIN SAID CHAMBER AND HAVING A GROOVE IN THE EXTERNAL SURFACE THEREOF, A TRIGGERING SPRING DISPOSED WITHIN SAID CHAMBER AND ARRANGED TO EXERT FORCE UPON SAID ACTUATING PIN WHEN SAID ACTUATING PIN IS DEPRESSED THEREAGAINST, SAID FRAME HAVING A TRANSVERSE OPENING EXTENDING THERETHROUGH DISPOSED TO INTERSECT SAID CHAMBER AND TO CONFRONT SAID GROOVE ON SAID ACTUATING PIN WHEN SAID ACTUATING PIN IS IN A COCKED POSITION DEPRESSED AGAINST SAID TRIGGERING SPRING, AND A RETAINING PIN DISPOSED WITHIN SAID TRANSVERSE OPENING AND ARRANGED TO ENGAGE WITHIN SAID GROOVE FOR RETAINING SAID ACTUATING PIN IN SAID COCKED POSITION, AND MEANS INTERCONNECTING SAID TIMING DEVICE AND SAID TRIGGERING APPARATUS, SAID INTERCONNECTING MEANS INCLUDING AT LEAST ONE ELONGATED ROCKER ARM PIVOTALLY ATTACHED CENTRALLY THEREOF TO SAID FRAME, THE UPPER END OF SAID ROCKER ARM BEING ENGAGEABLE WITH SAID RETAINING PIN AND THE LOWER END THEREOF BEING ENGAGEABLE WITH SAID LONGITUDINALLY EXTENDING PLANE SURFACE ON SAID WEIGHT, SAID ROCKER ARM BEING ARRANGED WHEREBY WHEN SAID LOWER END THEREOF IS IN ENGAGEMENT WITH SAID PLANE SURFACE SAID UPPER END THEREOF WILL ENGAGE AND HOLD SAID RETAINING PIN IN POSITION TO SECURE SAID ACTUATING PIN, SAID PLANE SURFACE HAVING A RECESS THEREIN NEAR ONE END THEREOF OF A SIZE TO RECEIVE SAID LOWER END OF SAID ROCKER ARM, SAID LOWER END OF SAID ROCKER ARM AND SAID RECESS BEING BROUGHT INTO REGISTRY WHEN SAID WEIGHT IS SUFFICIENTLY SHIFTED IN RESPONSE TO G-FORCES OVER A PERIOD OF TIME AS DETERMINED BY SAID TIMING DEVICE, WHEREUPON SAID ROCKER ARM WILL PIVOT AND SAID RETAINING PIN AND SAID ACTUATING PIN WILL BE RELEASED. 